feat: add NotSupportedError type

Author: asalkeld

pkg/functiondockerfile/generate.go

@@ -61,7 +61,7 @@ func Generate(f *stack.Function, version, provider string, fwriter io.Writer) er
 	}
 	generator, ok := generators[rt]
 	if generator == nil || !ok {
-		return errors.New("could not build dockerfile from " + f.Handler + ", extension not supported")
+		return utils.NewNotSupportedErr("could not build dockerfile from " + f.Handler + ", extension not supported")
 	}
 	return generator(f, version, provider, fwriter)
 }

pkg/provider/generator.go

@@ -28,6 +28,6 @@ func NewProvider(s *stack.Stack, t *target.Target) (types.Provider, error) {
 	case "local":
 		return local.New(s, t)
 	default:
-		return nil, nil
+		return nil, utils.NewNotSupportedErr(fmt.Sprintf("provider %s is not supported", t.Provider))
 	}
 }

pkg/provider/local/storage.go

@@ -44,7 +44,7 @@ func (l *local) storage(deploymentName string) error {
 	consolePort := uint16(ports[1])
 
 	minioImage := "minio/minio:latest"
-	err = l.cr.Pull(minioImage)
+	err = l.cr.ImagePull(minioImage)
 	if err != nil {
 		return err
 	}

pkg/utils/errors.go

@@ -17,6 +17,7 @@
 package utils
 
 import (
+	"errors"
 	"strings"
 	"sync"
 )
@@ -58,3 +59,21 @@ func (e *ErrorList) Aggregate() error {
 	}
 	return e
 }
+
+// NotSupportedError indicates that a request operation cannot be performed,
+// because it is unsupported.
+// Functions and methods should not return this error but should instead
+// return an error including appropriate context that satisfies
+//     errors.Is(err, errors.NotSupportedError)
+// either by directly wrapping NotSupportedError or by implementing an Is method.
+type NotSupportedError struct {
+	error
+}
+
+func NewNotSupportedErr(message string) error {
+	return &NotSupportedError{error: errors.New(message)}
+}
+
+func (*NotSupportedError) Is(err error) bool {
+	return strings.Contains(err.Error(), "unsupported") || strings.Contains(err.Error(), "not supported")
+}